What if I told you there was a food that cook be cooked in minutes, in a variety of ways, eaten with just about anything, for breakfast, lunch, or dinner, AND costs next to nothing?
Yeah, that’s pretty much why eggs are one of my favorite things. They call them incredible for a reason! We’ll be talking about the nutritional and compositional breakdown of eggs, how to store and prepare eggs, and how they can be used in different dishes! For simplicity’s sake, I’ll be talking about large chicken eggs, but there are obviously a variety of kinds! (Duck, teeny tiny adorable quail eggs, etc.)
The Origin of Eggs
It doesn’t matter which came first, because all we need to know is that chickens lay eggs, and if they’re unfertilized, we eat them! It takes 24 hours for a chicken to make and lay an egg, 20 of which is just to form the shell. Chickens can lay eggs daily, as long as they’re receiving enough light. Depending on the breed of chicken, the egg shell may be white or brown. It’s a common misconception that brown eggs are healthier than white eggs. They’re actually exactly the same, nutritionally.
Egg-laying hens never receive hormones in the United States. If you see “hormone-free” on an egg carton, it’s just a selling point – they’re all hormone free!
“Free range” is the key word that causes some controversy. Technically, there are no regulations to the duration or quality of outdoors time the hens receive. There just needs to be an open door that the chickens can choose to go out, and it could lead to a teeny tiny patch of dirt. Otherwise, conditions can be absolutely horrible. Your best bet is to get local eggs. My dad actually lives down the street from a women whose chickens run around her yard, and she collects the eggs and keeps them in her garage. Her neighbors can come and take eggs and leave a dollar in exchange as they please. Talk about fresh eggs!
The Composition of Eggs
Most of us are familiar with some parts of the egg, right? There’s the white, the yolk, and the shell. But there are a few little details as well that I’d like to touch on.
The yolk is the yellow center of the egg and contains all of the dietary fat. Many people choose not to eat the yolk because of its fat content, but it also contains fat-soluble vitamins, iron, and half of the protein in the entire egg!
Holding the yolk in the center of the egg is the chalazae – that white, stringy part. This is an important part of the egg when a little chick is starting to form, as it keeps it suspended and safe from being knocked around. For our purposes, it keeps the yolk whole and intact and prevents it from breaking within the shell. It’s totally not gross and perfectly okay to eat! When you cook the egg, it’ll become part of the white and you won’t even know it’s there.
The egg white is actually called the albumen. It contains no fat, a little more than half the protein, and some vitamins and minerals.
If you’ve ever hard-boiled an egg, you’ve probably noticed the very thin membrane covering the whole egg white. There are actually a few very thin membranes which protect against bacterial infections.
At the fatter end of the egg there is a little pocket of air between two of the membranes. In a fertilized egg, this air pocket serves as the chick’s first breath before it breaks out of the shell. For us, it can help us tell if we are working with a fresh or older egg by it’s size.
The outer shell is made of calcium carbonate. It keeps the whole egg in that nice egg-shape, and allows the exchange of gases through its pores. While we don’t eat the shell, it wouldn’t actually hurt. Many people use the shell as compost to help their plants grow and mineralize the soil!
Eggs are great sources of protein, relatively low calorie, and are full of a spattering of vitamins and minerals. They are high in cholesterol, though, which has been causing much debate lately, but has been previously linked to heart disease. The yolk is the only part that contains cholesterol, so if you are watching that, opt for egg whites!
Purchasing and Selecting Eggs
Eggs come in styrofoam or cardboard cartons to prevent them from knocking around and breaking, but they aren’t foolproof. Always open the carton and check for cracks or oozing egg white before purchasing. Spin each egg to make sure they aren’t stuck to the carton – an indication of a crack at the bottom of the egg.
Eggs are categorized by size. We’ve been talking about large eggs, but they come in small, medium, large, extra large, and jumbo! This goes by weight, and will alter the nutritional facts a bit.
Eggs can also be graded. You’ve probably seen AA, A, and B. These refer to the freshness of the egg, and are determined by the size of the air cell. As an egg ages, gases escape into the air cell and it expands.
Egg substitutions like a carton of egg whites are an option to purchase, but remember that while they may not have fat or cholesterol, they have no fat soluble vitamins or iron, and most likely have added sodium as a preservative. These eggs are often pasteurized, which means they are safer to eat raw or partially cooked.
The expansion of the air cell as an egg ages gives us a great way to check for freshness at home. If you place an egg in a tall glass of water, you can determine its freshness. If it sinks, it’s fresh! Standing on it’s tip, and you should use it soon. If it floats, do not use that egg! Too much time has passed and it’s probably not safe to eat!
Another way to tell freshness is by cracking the egg and looking at it from the side. A fresh egg will have a fat, tall yolk and tight white. As an egg ages, the yolk will flatten out and the white will spread out more.
If you crack an egg and the white is cloudy, you have a SUPER fresh egg on your hands. (Although hopefully you didn’t just crack an egg into your hands…)
Of course, if an egg has a bad odor, do not eat it!!
In the US, our eggs need to be stored in the fridge. Some refrigerators have a cute little spot in the door where you can transfer your eggs from the ugly carton. It’s actually a bad idea to keep your eggs in the door! Every time you open your fridge, the eggs are exposed to a change in temperature which causes faster degradation. Plus, they’ll get jostled around with every open and close of the fridge door. It’s best to keep them on a shelf toward the back of the fridge, where they are least likely to be exposed to changes in temperature. The original carton they came in is fine 🙂
One thing I really love about eggs is the great variety in ways to prepare them. They can be fried, baked, poached, scrambled, made into an omelet, hard boiled, soft boiled, OMG!
Not to mention, eggs serve many functions as an ingredient in other recipes – as part of hollandaise sauce, in baked goods, as a coating for bread crumbs on a chicken breast, you name it! Eggs provide flavor, color, help to emulsify or thicken, bind, coat, leaven, and prevent crystallization in food.
The key to cooking eggs is to keep them at a low-medium heat for short periods of time. Coagulation is a gross-sounding word, but it just means that the proteins are being denatured and taking on a different form. The egg whites going from clear when raw to white when cooked is just the proteins coagulating.
It’s important to keep in mind that milk and sugar will increase coagulation time (which means the eggs will take longer to cook). Salt and acid, on the other hand, decrease coagulation time, making the process happen faster.
Sometimes when you hard boil an egg, you’ll see a green ring around the yolk. That’s okay to eat, it’s just a little unsightly. What this is is the iron from the yolk mixing with the sulfur in the white, creating iron sulfide. This is just an indication that the egg was cooked too long!
What do you guys think? Do you eat eggs, and what is your favorite way to prepare them? Did you learn anything awesomely new? I’d love to hear from you!
Bonus: Here’s a photo of my cat trying to be sneaky and steal my eggs. He swiped a few times but couldn’t reach. Bad Momo!